Inter-rater Reliability of Tooth Shade Selection by Conventional Visual Method and Intraoral Camera: An In-vivo Study

Introduction: Visual shade matching has been practiced in dentistry for decades to find a shade of restoration that perfectly match with adjacent tooth for natural aesthetic look. Intraoral camera is an adjunct tool for visual shade matching that can reduce the shortcomings of conventional method. It is especially beneficial for subjective shade matching with in-built optimal lighting conditions while eliminating all environmental influences. The study’s rationale is to determine whether or not external lighting and background affect a clinician’s visual shade-matching performance. Aim: To determine the inter-rater reliability of shade matching by conventional visual method and using intraoral camera (SOPRO 717) assisted visual method, while taking account into the environmental influence on visual shade matching. Materials and Methods: The study was conducted in-vivo in the Department of Prosthodontics, Guru Nanak Institute of Dental College and Hospital in Kolkata West Bengal, India, over a period of 18 months from May 2022 to November 2023. Five dental professionals with normal colour vision performed the shade selection procedure on 30 patients of 24 to 60 years. Each dental professional or examiner matched the shade of tooth with VITA System 3D-Master® shade guide by conventional visual method and with intraoral camera; before and after the insertion of restoration. Chi-square test was used to determine the reliability among examiners and p-value<0.05 was considered to be statistically significant. Results: When two methods were compared, it showed that shade selection using intraoral camera was more aligned with the selected shades based on consensus than conventional method. The Chi-square statistic was 24.6544. The p-value was <0.00001 (significant at p<0.05). Reliability among five raters or examiners showed statistically significant difference (p<0.05) for conventional visual method indicating less agreement level among examiners. Whereas agreement level was higher for intraoral camera. Conclusion: Intraoral camera is a reliable assistance for visual shade selection as it reduces certain level of subjectivity and help the observer for easy decision making by increasing the agreement level.